> I don't see how anybody says they'd move a large company to kubernetes in such an environment in a few months with no screwups and solid testing.

Unfortunately, I do. Somebody says that when the culture of the organization expects to be told and hear what they want to hear rather than the cold hard truth. And likely the person saying that says it from a perch up high and not responsible for the day to day work of actually implementing the change. I see this happen when the person, management/leadership, lacks the skills and knowledge to perform the work themselves. They've never been in the trenches and had to actually deal face to face with the devil in the details.